The present invention relates to an ink cartridge for an ink-jet recording apparatus, and an ink-jet recording apparatus. More specifically, the present invention relates to an ink cartridge provided with an ink supply opening having a packing member, and an ink-jet recording apparatus having the ink cartridge.
Since a graphic process can be executed relatively easily owing to development of personal computers, a recording apparatus has been required, which can output a high quality hard copy of, for example, a color image shown on a display. In order to respond to such a demand, a recording apparatus mounting an ink-jet recording head thereon has been provided.
Since the ink-jet recording apparatus is relatively small in printing noise and can form small dots at a high density, the ink-jet recording apparatus is used for many kinds of printing including color printing.
For ink supply to a recording head in the ink-jet recording apparatus during printing and recording, an ink supply needle communicating with the recording head for ejecting ink is inserted into an ink supply opening of an ink cartridge for an ink-jet recording apparatus so that the ink in the ink cartridge is sent to the recording head via the ink supply needle. In order to prevent problems, such as drying of the ink by the contact with the outside air and introduction of air bubbles in the ink, the ink supply needle is formed using an olefin based amorphous polymer high in molding property and extremely low in gas permeability, while the ink supply opening is provided with a packing member closely contactable with the outer circumference of the ink supply needle, thereby securing the sealing property of an ink channel. Since ink replenishment is executed by replacing ink cartridges, the ink supply opening of the ink cartridge and the ink supply needle should be attached or detached easily. For this reason, a butyl rubber is widely used as a material of the packing member.
However, the butyl rubber is not always stable with respect to various kinds of ink, and thus the butyl rubber may cause an unsatisfactory result when used in combination with certain kinds of ink. Moreover, since molding of the butyl rubber is accomplished, in general, by a compression molding method, the dimensional accuracy is unstable due to irregularity of the material thickness. Therefore, in practice, finish inspection for all of products is required to ensuring the product quality.
As a material to be adopted in place of the butyl rubber having the aforementioned disadvantage, a thermoplastic elastomer is conceivable, which exhibits rubber elasticity in an ordinary temperature but plastic and moldable property by application of heat. The thermoplastic elastomer is high in stability with respect to ink, and also high in dimensional accuracy because the thermoplastic elastomer can be molded using an ordinary injection molding method.
However, in the case such a thermoplastic elastomer is used for a packing member in an ink supply opening of an ink cartridge for an ink-jet recording apparatus, and the packing member is closely contacted with an ink supply needle by inserting the ink supply needle into the ink supply opening, the ink supply needle made, in particular, of an olefin based amorphous polymer is deformed after a certain time so that it is difficult to pull out the ink supply needle from the ink supply opening of the ink cartridge as well as to insert the ink supply needle into an ink supply opening of a new ink cartridge. This will cause a malfunction of the ink-jet recording apparatus.
In view of the above-mentioned problems, the invention has been achieved, and an object thereof is to provide an ink cartridge, adapted for an ink-jet recording apparatus, which comprises an ink supply opening having a packing member high in corrosion resistance with respect to various kinds of inks, stable in molding process accuracy, and free from the risk of causing a malfunction of the ink-jet recording apparatus. Another object of the present invention is to provide an ink-jet recording apparatus having such ink cartridge.
As a result of elaborate experiments by the present inventors, it was found out that the above-mentioned object can be achieved by adjusting the amount of a polyethylene oil to be added generally to a thermoplastic elastomer for obtaining an appropriate flowability required at the time of molding, and an appropriate rubber hardness of a member required after molding. That is, the technological configuration and the effects of the invention are as follows.
An ink cartridge for an ink-jet recording apparatus according to a first aspect comprises an ink supply opening having a packing member capable of closely contacting with the outer circumference of an ink supply needle provided in an ink-jet recording apparatus main body, wherein the packing member is made of a thermoplastic elastomer containing 25% or less by weight of a polyethylene oil. Since the packing member is made of a thermoplastic elastomer, a packing member with a high corrosion resistance with respect to various kinds of inks, and a stable molding process accuracy can be provided. Moreover, since the thermoplastic elastomer contains 25% or less by weight of a polyethylene oil, in the case of inserting an olefin based amorphous polymer ink supply needle in an ink supply opening, the packing member can hardly degrade the quality of the olefin based amorphous polymer ink supply needle. Therefore, an ink cartridge for an ink-jet recording apparatus comprising an ink supply opening having a packing member without the risk of causing a malfunction of the ink-jet recording apparatus can be provided.
In the ink cartridge for an ink-jet recording apparatus according to a second aspect, the rubber hardness of the thermoplastic elastomer is 40 to 70 (Shore hardness). Accordingly, the packing member and the ink supply needle can be contacted particularly closely so that the sealing property of the ink channel can be maintained further certainly. Therefore, an ink cartridge for an ink-jet recording apparatus capable of preventing problems such as drying of the ink by the contact with the outside air, and introduction of bubbles can be provided.
In the ink cartridge for an ink-jet recording apparatus according to a third aspect, the packing member comprises a contact tongue piece tilingly protruded into an interior of the packing member so as to contact with the outer circumferential surface of the ink supply needle. The contact tongue piece can easily be deformed elastically so that stable contact with the ink supply needle can be ensured by tolerating, for example, size displacement in mounting. Therefore, an ink cartridge for an ink-jet recording apparatus capable of preventing problems such as drying of the ink by the contact with the outside air, and introduction of bubbles can be provided.
An ink-jet recording apparatus according to a fourth aspect comprises an ink supply needle communicating with an ink-jet recording head, wherein an ink supply opening of an ink cartridge for an ink-jet recording apparatus is closely contacted with the ink supply needle via a packing member, which is made of a thermoplastic elastomer containing 25% or less by weight of a polyethylene oil. Since the packing member is made of a thermoplastic elastomer, a high corrosion resistance with respect to various kinds of inks can be provided to the packing member, and a molding process accuracy of the packing member can be stabilized. Moreover, since the thermoplastic elastomer contains 25% or less by weight of a polyethylene oil, in the case of inserting an olefin based amorphous polymer ink supply needle in an ink supply opening, the packing member can hardly deform the olefin based amorphous polymer ink supply needle. Therefore, an ink-jet recording apparatus with an ink supply opening of an ink cartridge for an ink-jet recording apparatus closely contacted via a packing member without the risk of causing a malfunction of the ink-jet recording apparatus can be provided.
In the ink-jet recording apparatus according to a fifth aspect, the rubber hardness of the thermoplastic elastomer is 40 to 70 (Shore hardness) . Accordingly, the packing member and the ink supply needle can be contacted particularly closely so that the sealing property of the ink channel can be maintained further certainly. Therefore, an ink-jet recording apparatus capable of preventing problems such as drying of the ink by the contact with the outside air, and introduction of bubbles can be provided.
In the ink-jet recording apparatus according to a sixth aspect, the packing member comprises a contact tongue piece tiltingly protruded into an intetior of the packing member so as to contact with the outer circumferential surface of the ink supply needle. The contact tongue piece can easily be deformed elastically so that stable contact with the ink supply needle can be ensured by tolerating, for example, size displacement in mounting. Therefore, an ink-jet recording apparatus capable of preventing problems such as drying of the ink by the contact with the outside air, and introduction of bubbles can be provided.
The present disclosure relates to the subject matter contained in Japanese patent application No. 2000-2277 (filed on Jan. 11, 2000), which is expressly incorporated herein by reference in its entirety.